Returning a value from Cordova File Plugin when called from a function

问题

I have seen someone has posted a similar question but it doesn't really fit what I'am looking for:

Here is my code:

$(document).ready(function(){
  $("#btnTest").bind("click", function(){
    a = createFile();
      alert(">> "+a); // Displayed returned value;
  });

  function createFile(){
    var type = window.TEMPORARY;
    var size = 5*1024*1024;
    window.requestFileSystem(type, size, successCallback, errorCallback)

    function successCallback(fs) {
      fs.root.getFile('log.txt', {create: true, exclusive: true}, function(fileEntry) {
        alert('File creation successfull!');
        return 1; // Return value;
      }, errorCallback);
    }

    function errorCallback(error) {
      alert("ERROR: " + error.code)
      return 2; // Return value;
    }
    }   
});

Basically once the createFile() function is called it will return either 1 (success) or 2 (error). Problem is I do not know how I can return the value and call it properly?

Any help would be really good.

回答1:

I would create a global variable in your function called returnValue and set its value

$(document).ready(function(){
  $("#btnTest").bind("click", function(){
    a = createFile();
      alert(">> "+a); // Displayed returned value;
  });

  function createFile(){
    var returnValue;
    var type = window.TEMPORARY;
    var size = 5*1024*1024;
    window.requestFileSystem(type, size, successCallback, errorCallback)

    function successCallback(fs) {
      fs.root.getFile('log.txt', {create: true, exclusive: true}, function(fileEntry) {
        alert('File creation successfull!');
        returnValue = 1; // Return value;
      }, errorCallback);
    }

    function errorCallback(error) {
      alert("ERROR: " + error.code)
      returnValue = 2; // Return value;
    }
    return returnValue;
  }
    
});

来源：https://stackoverflow.com/questions/65766037/returning-a-value-from-cordova-file-plugin-when-called-from-a-function